package com.company;

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import java.util.stream.Collectors;

/**
 * @author Administrator
 */
public class HJ10字符个数统计 {
    public static void main(String[] args) {

        List<String> stringList = new ArrayList<>();
        Scanner scanner  = new Scanner(System.in);
        String line = scanner.nextLine();
        for (int i = 0; i < line.length(); i++) {
            stringList.add(line.substring(i, i+1));
        }
        List<String> collect = stringList.stream().distinct().collect(Collectors.toList());
        System.out.println(collect.size());
    }
}

